Better and more capable tool materials allow machine tools to cut at increasingly higher speeds and feeds. Inrecent decades, high speed machining has received an important interest as a technological solution for high productivityto increase economic efficiency in manufacturing. The recent developments of cutting tool materials in high speed ma-chining are reviewed. The appropriate applications of the high speed machining technology are presented. It can concludethat the optimal matching of meehardcal, physical, end chemical properties between teol and workpieee materials is veryimportant in high speed machining. The researeh is very grit beneficial to the design and the selection of re431 materials hihigh speed machining.

在机械加工领域，切削加工是应用最广泛的一种加工方法，其发展方向主要是研究高速切削，对超硬材料加工，主要是发展磨削、超声和放电等高效复合加工技术。文章介绍高效切削加工和高效复台加工技术的理论研究和技术开发与应用及所取得的重要成果，主要包括高建切削基础理论、陶瓷刀具材科研究新体系和超硬材料断续磨、超声和电火花的复台加工理论与技术的研究开发。生产实际应用结果表明，高效加工技术可以大幅度提高加工技率。改善加工表面质量，降低加工成本。

An experimental investigation is carried out to coat two types of carbide powders, TiC and (W, Ti) C, with an alumina ceramic using a sol-gel technology. The coated carbide powders are then fabricated into two kinds of new ceramic tool materials by the hot pressing method. A scanning electron microscopy (SEM) observation reveals that the matrix (carbide) grains are uniformly coated with the alumina ceramic and the new tool materials have a homogeneous microstructure. The tests of mechanical properties and wear resistance in machining are finally conducted. It is shown that the new tool materials can increase the tool-life by up to 100% as compared to other ceramic tool materials when machining a mild carbon steel, while the fracture toughness is improved by up to 33%. When compared with a hard coated carbide tool, the new materials exhibit a superior ability in maintaining the wear resistance during the entire tool-life.

A model for designing functionally gradient ceramic tool materials with symmetrical distribulion is presented for the first time.fiased on the analysis of slress distribution for ceramic tools in the cutting process, the design of composition dlstrifiution was carried out with the aim of partial relaxation of stresses resuhing from external Ioadings by residual thermal stress in fabricaring process by means of finite element analysis of residual thermal stress for gradient ceramic tool malerials wilh differentcomposirional distributions. The principle for oprimal design was also proposed. An Al2O3/TiC funclionally grodlent ceramic toolmaterial. FG-I. was accordingly synlhesized by hot pressing.

Though there are already a varlety of models for comples, they are not so convenientneeded in practice. A hlerchical model and the principle of decomposition and reconstitution for complex surfaceshave beem proposed, which have the potential to enhance the support of automated design systems on creative work intelligently. Then the progress made is discused involving the application of the new principle in the following threeareas; conugation sudace calculation, tool path generation in numercally controlled machining, and maching proccessinnovation By re-recognition.

研究了不同SiC晶须音量的Al2O3/TiB2/SiCw陶瓷刀具材料的断裂韧性随温度的变化规律。结果表明：Al2O3/TiB2/SiCw陶瓷材料的K1e在1000℃内随温度的升高而增大；晶须含量越高，K1e增幅越大。通过计算分析表明：随温度的升高断裂时拔出的晶须大大增多。当晶须体积含量（下同）为20%时，Al2O3/TiB2/SiCw陶瓷在室温时只有长径比小于2.87的晶须在断裂时才有可能产生拔出，而在900℃时长径比小于10的晶须都能产生拔出。在同样温度条件下，晶须含量越高所能产生拔出的晶须增多。当晶须含量为40%时（晶须长径比为10），在温度大于620℃时能产生晶须的拔出，而当晶须含量为18%时, 只有温度大于940℃才能产生拔出。晶须含量越高其高温增韧效果越强。

A new ceramic cutting fool material has been developed by means of silicon carbide whisker (SiCw) reinforcement and silicon carbide particle (SiCp) dispersion. The material has the advantage of high bending strength and fracture tougbness. Compared with the mechanical properties of Al2O3(A), Al2O3/SiCp(AP), Al2O3/SiCw(AW), Al2O3/SiCw(JX-1) and Al2O3/SiCp/SiCw(JX-2), it confirms that JX-2 composite has obvious additive effect of both reinforcing and toughening. The reinforcing and toughening mechanisms of JX-2 composite have been studied based on the analysis of thermal-expansion mismatch and the observation of microstructure, Synergistic effects of toughening and strengthening for JX-2 have been researched systematically.

A review of advanced ceramic tool material, including its development, app]ication and the new trend in research, is offered in this article. As one of the most important tool materials to be used in the next century, advanced ceramic material has great potential and broad prospects. The major subject in the future study is the development of new type of ceramic tool material and finding ways to increase its strength and toughness as well as its reliability. The imperative task at present is how to popularise ceramic tools and how to use them more efficiently and reasonably.

A new criterion of fracture mechanics-stochastic characteristics for cemented carbide tool fracture in consideration of cutting temperature effect is proposed in the paper. Experimental results show that the theoretical tool life by fracture obtained from the criterion proposed for tool fracture presents a good agreement with the experimental one.

A new criterion of fracture mechanics-stochastic characteristics for ceramic tool fracture based on the analysis of its fracture features in intermittent turning, is proposed in the paper. A series of experiments on mechanical performance for ceramic tool as well as cutting tests on tool life by fracture have been done. The stresses in tool tip are analysed by finite element method Allof these show that the modified distribution function of theoretical tool life by fracture derived from the mentioned new criterion presents a good agreement with the experimental results, SEM analysis on the tool fracture faces indicates the late fracture of ceramic tool appears in fatigue features